1. Field of the Invention
The present invention relates to a battery monitoring system configured to monitor a voltage of a battery.
FIG. 4 is a configuration diagram of a related-art battery monitoring system. The related-art battery monitoring system includes a combination of a primary battery monitoring IC 700 and a secondary battery monitoring IC 600. The primary battery monitoring IC 700 is configured to monitor a voltage, a charge/discharge current, an ambient temperature, and the like of a battery block 400, to thereby detect an abnormality, e.g., an overvoltage state of the battery block 400. The secondary battery monitoring IC 600 has the almost same function as the primary battery monitoring IC 700, and is thus similarly configured to monitor the battery. The related-art battery monitoring system is configured to output detection signals to a host controller 500 from those battery monitoring ICs. The primary battery monitoring IC 700 and the secondary battery monitoring IC 600 each include a reference voltage circuit, and are configured to monitor a voltage and the like of the battery block 400 based on respective reference voltages.
2. Description of the Related Art
When the primary battery monitoring IC 700 cannot normally operate anymore due to troubles and other causes, the secondary battery monitoring IC 600 continues the monitoring operation, thereby enabling the safety of the battery monitoring system to be maintained.
However, there is a problem in that, even when the primary battery monitoring IC 700 or the secondary battery monitoring IC 600 is damaged during its operation, and then the characteristics of the reference voltage circuit are deteriorated, monitoring of the battery may be continued based on a deteriorated reference voltage.